Safety device for clutch mechanism



April 19, 1927.

d. B. MONAHAN SAFETYDEVICE FOR CLUTCH MECHANISM Filed May 28, 1925 2 Sheets-Sheet 1 We ATTORNEY Ap 9 JQB. MONAHAN SAFETY DEVICE FOR CLUTCH MECHANISM Filed May 28. i925 2 Sheets-Sheet 2 .IIA

I u HIIIIII iiliil lllllll qml Q Q -13 A ay E !!!!-a J A Ii INVENTOR Janis 5. JWO/V/Mfi/W ATTORNEY Patented Apr. 19, 1927.

UNITED STATES JAMES B. MONAHAN,

OF NEW YORK, N. Y., ASSIGNOR T LITHO ETGHING CORPORA- 1,625,945 PATENT OFFICE.

TION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

SAFETY DEVICE FOR CLUTCH MECHANISM.

Application filed May 28, 1925. Serial No. 33,330.

This invention relates generally to safety devices for clutch mechanism and has for its main object and feature the production of means whereby it is impossible for the operator to throw in the clutch or release a drop member unless his hands are outside the zone of danger.

In the accompanying drawings the invention is disclosed in a concrete and preferred form in which:

Fig. 1 is a general view of a punching press or the like with the device of the invention shown in position.

Fig. 2 is a fragmentary view of the framework of the machine showing the two push buttons for releasing the safety lock.

Fig. 3 is a plan view, partly in section and with parts broken away of the device of the invention.

Fig. 1 is a vertical sectional view on the plane of line 4t-t of Fig. 3.

Fig. 5 is a diagram showing connections. 1

1 is a punching press or the like in which member 2 drops or is otherwise actuated as by cam means when a clutch is thrown in by moving controlling rod or member 3 by means of foot pedal or actuating member 4 all in a manner well understood.

Controlling member 4 has an enlargement or collar 5. 6 and 7 indicate two arms, constituting a safety lock, pivotally supported at S and connected by spring 9 to thereby normally move said arms into the plane of or beneath said collar; and it will be understood that when the arms are in this position controlling member 4% cannot descend. and the clutch cannot be thrown in. 10 is an electro-inagnet having an armature 11 pivotally supported at 12 and this armature extends between the arms and serves to spread them out of the plane of collar 5' when the magnet is energized. This magnet is of sufficient strength to overcome the tension of spring 9, but. if rod a is under compulsion to move as when the operator steps on the pedal before closing a circuit through the magnet, then the weight of the operators foot is suflicient to prevent the magnet from moving the armature to separ rte the arms and the device remains locked.

The device is enclosed within a casing 13 and in this casing there is a plate lat on which arms 6 and 7 are pivoted and from which the magnet is suspended. Bolts as 15 the electrical are within the casing for securing it to frame 16 of the machine and the top of the casing is closed by a cover 1? locked by means of lock 18. Controlling rod 3 extends through the casing and its collar 5 is secured to it by screw 19 inaccessible for removal except when the cover is removed. 20 indicates a member ,pivotally supported on plate 14 which when turned in one direction (indicated in full lines in Fig. 3) permits arms 6 and 7 to come together, but which when turned into the dotted line position (Fig. keeps the arms spread apart and thus renders the safety lock inoperative. It will be seen therefore that the parts of the safety device are not accessible from the outside of the casing and access can only be gained to the inside by an authorized person having a key; it will also be seen that should the operator absent-mindedly place his foot on the pedal before unlocking the safety lock the device will not unlock when' the magnet is energized.

Any suitable means may be used to energize magnet 10. Preferably it is included in a normally open circuit 21 in which two push buttons 22 are arranged in series. These buttons have to be pressed simultaneously to close the circuit and are so arranged on the framework (Fig. 2) that the fingers of one hand will not span both buttons. The operator must therefore use both hands to close the circuit and his foot must be off the pedal before the device is released.

I claim:

1. A safety device including: a reciprocable controlling member, a collar on said member, two pivotally supported arms normally urged into the plane of the collar to prevent movement of the controlling mein- 3 her, an electro-magnet to be energized at will, and an armature controlled by the electro-magnet to spread the arms apart and into positions beyond the plane of the collar.

2. A safety device including: a controlling member, a safety lock to normally look the controlling member, an electro-magnet to unlock the safety lock only when the controlling member is free from compulsion to.

move.

Signed at New York city, in the county of Bronx and State of New York this 141th day of May, 1925.

JAMES B. MONAHAN.

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